Ultrasound diagnostic apparatus, ultrasound image display method and computer-readable recording medium

ABSTRACT

An ultrasound diagnostic apparatus generates and displays an ultrasound image corresponding to reflected ultrasound reflected inside a subject. The ultrasound diagnostic apparatus includes a hardware processor that generates a B-mode image based on a reception signal corresponding to the reflected ultrasound, analyzes the B-mode image and determines an operation status of a treatment instrument used for treatment, and based on a result of the determination, displays a first display image including a current B-mode image and a second display image including a B-mode image obtained when the treatment instrument is in a non-operating state in such a manner that the first display image and second display image are aligned.

CROSS REFERENCE TO RELATED APPLICATIONS

The entire disclosure of Japanese Patent Application No. 2018-190444filed on Oct. 5, 2018 is incorporated herein by reference in itsentirety.

BACKGROUND Technological Field

The present invention relates to an ultrasound diagnostic apparatus, anultrasound image display method and a program and specifically relatesto a technique that is useful when a treatment instrument is insertedinto the body of a subject under ultrasound guidance and treatment isperformed.

Description of Related Art

Conventionally, as one of medical image diagnostic apparatuses, anultrasound diagnostic apparatus that transmits ultrasound toward asubject, receives waves reflected by the subject and performspredetermined signal processing on the reception signal to visualize ashape, a condition or behavior of the inside of the subject in the formof an ultrasound image is known. An ultrasound diagnostic apparatus canobtain an ultrasound image with a simple operation of applying anultrasound probe to a body surface or inserting the ultrasound probeinto the body and thus is safe and puts a smaller burden on the subject.

For example, an ultrasound diagnostic apparatus is used for treatment byinserting a treatment instrument into the body of a subject underultrasound guidance to, for example, suck soft tissue in a treatmentregion of interest. In such treatment, a surgeon such as a doctor caninsert the treatment instrument and perform treatment while viewing anultrasound image obtained by the ultrasound diagnostic apparatus toconfirm the treatment region of interest.

Where treatment is performed under ultrasound guidance, in order tograsp a correct position and range of a treatment region of interest, itis preferable that the treatment region of interest be clearly reflectedin an ultrasound image (B-mode image). However, injection of fluid (forexample, saline) from a treatment instrument inserted inside the body orultrasound irradiation may cause generation of noise (hereinafterreferred to as “spray pattern”) in the ultrasound image, resulting in adecrease in visibility of the treatment region of interest.

In an ultrasound treatment apparatus disclosed in Japanese PatentApplication Laid-Open No. 2000-229098, when treatment is performed usinga treatment instrument, a live image during the treatment and a stillimage picked up, for example, before the treatment are displayed toensure visibility of a treatment region of interest.

However, in the ultrasound diagnostic apparatus disclosed in JapanesePatent Application Laid-Open No. 2000-229098, a still image, forexample, one before treatment, is displayed in response to an input of adriving start signal from a treatment instrument and the ultrasounddiagnostic apparatus needs to include an interface for signaltransmission/reception to/from the treatment instrument.

Also, a still image picked up, for example, before treatment isdisplayed as it is and thus identification of a treatment region ofinterest may be difficult depending on the level of skills of thesurgeon.

SUMMARY

An object of the present invention is to provide an ultrasounddiagnostic apparatus, an ultrasound image display method and a programthat enable ensuring visibility of a treatment region of interest withno need for a special interface for connection with a treatmentinstrument.

Another object of the present invention is to provide an ultrasounddiagnostic apparatus that enables identifying a treatment region ofinterest easily irrespective of a level of skills of a surgeon.

To achieve at least one of the abovementioned objects, according to anaspect of the present invention, an ultrasound diagnostic apparatusreflecting one aspect of the present invention is an apparatus forgenerating and displaying an ultrasound image corresponding to reflectedultrasound reflected inside a subject, the apparatus comprising ahardware processor that

generates a B-mode image based on a reception signal corresponding tothe reflected ultrasound,

analyzes the B-mode image and determines an operation status of atreatment instrument used for treatment,

displays, based on a result of the determination, a first display imageincluding a current B-mode image and a second display image including aB-mode image obtained when the treatment instrument is in anon-operating state in such a manner that the first display image andthe second display image are aligned.

To achieve at least one of the abovementioned objects, according to anaspect of the present invention, an ultrasound image display methodreflecting one aspect of the present invention is a method forgenerating and displaying an ultrasound image corresponding to reflectedultrasound reflected inside a subject, the method comprising:

generating a B-mode image based on a reception signal corresponding tothe reflected ultrasound;

analyzing the B-mode image and determining an operation status of atreatment instrument used for treatment; and

displaying, based on a result of the determination, a first displayimage including a current B-mode image and a second display imageincluding a B-mode image obtained when the treatment instrument is in anon-operating state in such a manner that the first display image andthe second display image are aligned.

To achieve at least one of the abovementioned objects, according to anaspect of the present invention, a non-transitory computer-readablerecording medium reflecting one aspect of the present invention is amedium storing a program for causing a computer in an ultrasounddiagnostic apparatus for generating and displaying an ultrasound imagecorresponding to reflected ultrasound reflected inside a subject, toperform:

first processing for generating a B-mode image based on a receptionsignal corresponding to the reflected ultrasound;

second processing for analyzing the B-mode image and determining anoperation status of a treatment instrument used for treatment; and

third processing for displaying, based on a result of the determinationby the second processing, a first display image including a currentB-mode image and a second display image including a B-mode imageobtained when the treatment instrument is in a non-operating state insuch a manner that the first display image and the second display imageare aligned.

To achieve at least one of the abovementioned objects, according to anaspect of the present invention, an ultrasound diagnostic apparatusreflecting one aspect of the present invention is an apparatus forgenerating and displaying an ultrasound image corresponding to reflectedultrasound reflected inside a subject, the apparatus comprising ahardware processor that

generates a B-mode image based on a reception signal corresponding tothe reflected ultrasound,

determines an operation status of a treatment instrument used fortreatment,

displays, based on a result of the determination, a first display imageincluding a current B-mode image and a second display image including aB-mode image obtained when the treatment instrument is in anon-operating state in such a manner that the first display image andthe second display image are aligned, and highlights a treatment regionof interest in the second display image.

BRIEF DESCRIPTION OF DRAWINGS

The advantages and features provided by one or more embodiments of theinvention will become more fully understood from the detaileddescription given hereinbelow and the appended drawings which are givenby way of illustration only, and thus are not intended as a definitionof the limits of the present invention:

FIG. 1 is a diagram illustrating an outer appearance of an ultrasounddiagnostic apparatus according to an embodiment;

FIG. 2 is a diagram illustrating a configuration of an ultrasound probe;

FIG. 3 is a block diagram illustrating a major part of a control systemin the ultrasound diagnostic apparatus;

FIGS. 4A and 4B are diagrams illustrating an example of a B-mode imagewhen a treatment instrument is in a non-operating state and an exampleof a B-mode image when the treatment instrument is in an operatingstate, respectively;

FIG. 5 is a diagram illustrating an example of ultrasound image displayprocessing;

FIGS. 6A to 6C are diagrams for describing a method for determining anoperation status of the treatment instrument based on a brightnessdistribution; and

FIGS. 7A and 7B are diagrams illustrating example display images whenthe treatment instrument is in an operating state (during treatment) andexample display images when the treatment instrument is in anon-operating state (after treatment).

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, one or more embodiments of the present invention will bedescribed with reference to the drawings. However, the scope of theinvention is not limited to the disclosed embodiments.

An embodiment of the present invention will be described in detail belowwith reference to the accompanying drawings.

FIG. 1 is a diagram illustrating an outer appearance of ultrasounddiagnostic apparatus 1 according to an embodiment of the presentinvention. FIG. 2 is a diagram illustrating a configuration ofultrasound probe 20. FIG. 3 is a diagram illustrating a major part of acontrol system in ultrasound diagnostic apparatus 1.

Ultrasound diagnostic apparatus 1 is used together with a treatmentinstrument and visualizes a state of the inside of a subject in the formof an ultrasound image to support treatment using the treatmentinstrument. When treatment is performed using a treatment instrument, atreatment mode is selected in ultrasound diagnostic apparatus 1.

Examples of the treatment instrument include one that creates apressure-reduced portion at a distal end of a puncture part using theVenturi effect and sucks soft tissue of a treatment region of interestfrom the pressure-reduced portion to perform treatment (for example,TenJet (product name) manufactured by HydroCision, Inc.). The treatmentinstrument is equipped with a driving operation section, for example, afoot pedal, and can be activated/deactivated by operating the drivingoperation section.

FIG. 4A is a diagram illustrating an example of an ultrasound imageobtained in a non-operating state in which a treatment instrument is notactivated and FIG. 4B is a diagram illustrating an example of anultrasound image obtained in an operating state in which the treatmentinstrument is activated. Note that in each of FIGS. 4A and 4B, for easeof recognition of the inserted treatment instrument, puncture part N ofthe treatment instrument is illustrated with a line drawing superimposedthereon. The same applies to FIGS. 7A and 7B referred to later.

In the above-described treatment instrument, a significant amount offluid is ejected from a suction port provided in the pressure-reducedportion, high-brightness spray pattern SP spreading downward from adistal end of puncture part N of the treatment instrument is shown inthe ultrasound image (see FIG. 4B).

When the treatment instrument is inserted toward a treatment region ofinterest to perform treatment under ultrasound guidance, ultrasounddiagnostic apparatus 1 displays a live image during the treatment as afirst display image and a still image during a non-treatment period as asecond display image, in response to a change in operation status (forexample, activation/deactivation) of the treatment instrument. Since nospray pattern SP is shown in the second display image, visibility of thetreatment region of interest is ensured.

Note that ultrasound diagnostic apparatus 1 has no need to include aninterface for transmission/reception of a driving signal to/fromtreatment instrument, but may include such interface.

As illustrated in FIG. 1 , ultrasound diagnostic apparatus 1 includesultrasound diagnostic apparatus body 10 and ultrasound probe 20.Ultrasound diagnostic apparatus body 10 and ultrasound probe 20 areconnected via cable 30. Note that ultrasound probe 20 may be connectedto ultrasound diagnostic apparatus body 10 via wireless communication.

Ultrasound probe 20 transmits ultrasound to a subject, receives anultrasound echo resulting from reflection of the ultrasound by thesubject, converts the ultrasound echo into a reception signal andtransmits the reception signal to ultrasound diagnostic apparatus body10. For ultrasound probe 20, any electronic scanning probe such as aconvex probe, a linear probe or a sector probe or a mechanical scanningprobe such as a mechanical sector probe can be employed. The ultrasoundprobe 20 may include a puncture needle guide portion to which a punctureneedle is attached, the puncture needle guide portion guiding adirection of puncture.

As illustrated in FIG. 2 , ultrasound probe 20 includes acoustic lens21, acoustic matching layer 22, transducer array 23 and backing material24 in the order mentioned from the ultrasound transmission/receptionside. Note that a protective layer may be disposed on a surface ofacoustic lens 21 (ultrasound transmission/reception surface).

Acoustic lens 21 is a lens that converges ultrasound in a slicedirection (direction orthogonal to a scanning direction in which aplurality of transducers are aligned), and for example, when a material,a sound propagation speed of which is lower than that of a living body,is used for the acoustic lens, generally has a semicylindrical shape inwhich a central portion in the slice direction thereof bulges.

Acoustic matching layer 22 is an intermediate substance for makingultrasound efficiently enter the subject and matches an acousticimpedance of the transducers (not illustrated) and an acoustic impedanceof the subject with each other.

Transducer array 23 is formed of, for example, a plurality of striptransducers arranged in a single row in the scanning direction. In otherwords, ultrasound probe 20 is what is called a single-row probe.

Backing material 24 attenuates unwanted vibration caused by transducerarray 23.

Ultrasound diagnostic apparatus body 10 visualizes a shape, a conditionor behavior of the inside of the subject in the form of an ultrasoundimage (B-mode image), using the reception signal from ultrasound probe20.

As illustrated in FIG. 3 , ultrasound diagnostic apparatus body 10includes, for example, operation input section 11, transmission section12, reception section 13, image processing section 14, image storagesection 15, image display section 16, display section 17 and systemcontrol section 18.

Each of transmission section 12, reception section 13, image processingsection 14, image storage section 15 and image display section 16 isformed of, for example, a dedicated or general-purpose hardware(electronic circuit) for relevant processing, such as a DSP (digitalsignal processor), an ASIC (application-specific integrated circuit) ora PLD (programmable logic device), and provides a relevant function incooperation with system control section 18.

Operation input section 11 receives an input of, for example, a commandfor providing an instruction to, for example, start an examination orinformation relating to the subject. Operation input section 11 isformed of, for example, an operation panel including a plurality ofinput switches, a keyboard and a mouse. Note that operation inputsection 11 may be formed of a touch panel integrated with displaysection 17.

Transmission section 12 generates a transmission signal (driving signal)and outputs the transmission signal to ultrasound probe 20 according toan instruction from system control section 18. Although not illustrated,transmission section 12 includes, for example, a clock generationcircuit, a pulse generation circuit, a pulse width setting section and adelay circuit.

The clock generation circuit generates a clock signal based on which apulse signal transmission timing and a transmission frequency aredetermined. The pulse generation circuit generates a bipolarrectangular-wave pulse having a preset voltage amplitude in apredetermined cycle. The pulse width setting section sets a pulse widthof rectangular-wave pulses to be output from the pulse generationcircuit. The rectangular-wave pulses generated in the pulse generationcircuit are separated into different wirings for the respectivetransducers of ultrasound probe 20 before or after being input to thepulse width setting section. The delay circuit delays the generatedrectangular-wave pulses according to transmission timings for therespective transducers and outputs the generated rectangular-wave pulsesto the respective transducers.

Reception section 13 receives the reception signal from ultrasound probe20 and outputs the reception signal to image processing section 14according to an instruction from system control section 18. Although notillustrated, reception section 13 includes, for example, an amplifier,an A/D conversion circuit and a phase-adjustment/addition circuit.

The amplifier amplifies reception signals corresponding to ultrasoundsreceived by the respective transducers of ultrasound probe 20 at apredetermined amplification ratio set in advance. The A/D conversioncircuit converts the amplified reception signals into digital data at apredetermined sampling frequency. The phase-adjustment/addition circuitprovides delays to the respective reception signals resulting from theA/D conversion for the respective wirings for the transducers to adjusttime phases of the reception signals and adds up the reception signals(phase-adjustment and addition).

Image processing section 14 includes B-mode image generation section 141and image analysis section 142. Also, although not illustrated, imageprocessing section 14 includes a DSC (digital scan converter) thatperforms coordinate conversion and pixel interpolation according to thetype of ultrasound probe 20.

B-mode image generation section 141 generates a B-mode image indicatinga state of the inside of the subject based on the reception signal, inaccordance with an instruction from system control section 18. When thetreatment instrument is inserted inside the subject, puncture part N ofthe treatment instrument is shown in the B-mode image (see FIGS. 4A and4B). Also, spray pattern SP spreading from the distal end of puncturepart N toward a deep part is shown in a B-mode image during treatment inwhich the treatment instrument is active (see FIG. 4B).

Image analysis section 142 analyzes a B-mode image and determines achange in operation status of the treatment instrument. For example,image analysis section 142 determines whether the treatment instrumentis in an on-state (during treatment) or in an off-state (during anon-treatment period). A method for determination of a change in stateof the treatment instrument will be described later.

Image storage section 15 is formed of, for example, a non-volatilesemiconductor memory (what is called a flash memory) or a hard diskdrive. Image storage section 15 may be a disk drive that drives anoptical disk such as a CD (compact disc), a DVD (digital versatile disc)or a BD (Blu-ray disc (“Blu-ray” is a registered trademark)) or amagneto-optical disk such as an MO (magneto-optical disc) to read/writeinformation.

Image storage section 15 stores image data generated in B-mode imagegeneration section 141 on a frame-by-frame basis. The image data storedin the image storage section 15 is read out according to an instructionfrom system control section 18 and used for analysis by image analysissection 142 or used for display on display section 17.

Image display section 16 converts data of a B-mode image generated inimage processing section 14 (which may be data stored in image storagesection 15) into a display signal that is compatible with displaysection 17 and outputs the display signal according to an instructionfrom system control section 18. In the present embodiment, whenultrasound diagnostic apparatus 1 is used together with a treatmentinstrument, image display section 16 provides two-screen display inwhich two B-mode images are aligned (see FIGS. 7A and 7B). In thetwo-screen display, first display image D1 is a current B-mode image andsecond display image D2 is a B-mode image obtained when the treatmentinstrument is in a non-operating state.

Display section 17 is formed of, for example, a liquid-crystal display,an organic EL display or a CRT display. Display section 17 displays adisplay image based on a display signal from image display section 16,in accordance with an instruction from system control section 18.

System control section 18 performs overall control of ultrasounddiagnostic apparatus 1 by controlling operation input section 11,transmission section 12, reception section 13, image processing section14, image storage section 15, image display section 16 and displaysection 17 according to the respective functions.

System control section 18 includes, for example, CPU (central processingunit) 181, which serves as an arithmetic/control device, and ROM(read-only memory) 182 and RAM (random access memory) 183, which serveas a main memory device. A basic program and basic setting data arestored in ROM 182. Also, a treatment support program to be executed inthe treatment mode is stored in ROM 182. CPU 181 performs centralizedcontrol of operation of the respective functional blocks (transmissionsection 12, reception section 13, image processing section 14, imagestorage section 15, image display section 16 and display section 17) ofultrasound diagnostic apparatus body 10, by reading a program accordingto the content of processing from ROM 182, loading the program to RAM183 and executing the loaded program.

In the present embodiment, the functions of the respective functionalblocks are fulfilled by cooperation between the respective pieces ofhardware forming the functional blocks and system control section 18.Note that some or all of the functions of the respective functionalblocks may be fulfilled by execution of programs by system controlsection 18.

FIG. 5 is a flowchart illustrating an example of ultrasound imagedisplay processing where ultrasound diagnostic apparatus 1 is usedtogether with a treatment instrument. This processing is fulfilled, forexample, by execution of a predetermined program (treatment supportprogram) stored in ROM 182 by CPU 181 in response to enabling of thetreatment mode in ultrasound diagnostic apparatus 1. The enabling of thetreatment mode is performed by, for example, mode selection viaoperation input section 11.

In step S101, system control section 18 controls transmission section 12to transmit ultrasound from ultrasound probe 20.

In step S102, system control section 18 controls reception section 13 toacquire a reception signal corresponding to reflected ultrasound(ultrasound echo) received by ultrasound probe 20.

In step S103, system control section 18 controls image processingsection 14 (B-mode image generation section 141) to generate a B-modeimage based on the reception signal and store the B-mode image in imagestorage section 15.

In step S104, system control section 18 controls image display section16 and display section 17 to display a current B-mode image (live image)as first display image D1. Note that second display image D2 is notspecifically limited before a start of treatment using the treatmentinstrument (except resumption of treatment). For example, as seconddisplay image D2, a B-mode image before insertion of the treatmentinstrument may be displayed or the current B-mode image may bedisplayed.

In step S105, system control section 18 controls image processingsection 14 (image analysis section 142) to analyze a brightnessdistribution in the generated B-mode image. More specifically, systemcontrol section 18 generates a graph of brightness values in apredetermined region (see FIGS. 6A and 6B). FIG. 6A is a graph when thetreatment instrument is in a non-operating state and FIG. 6B is a graphwhen the treatment instrument is in an operating state.

Here, it is preferable that the predetermined region that is subject tothe analysis of the B-mode image be, for example, a deep region (regionDR surrounded by the dotted line in each of FIGS. 4A and 4B) in theB-mode image. When the present function is used, a user sets a displaydepth in such a manner that a treatment region of interest is displayedin an upper part with reference to a center of the screen. Therefore,the deep region (for example, a lower region corresponding to 20% of theB-mode image) is displayed as a relatively-low brightness (blackdisplay) image. Then, upon high-brightness spray pattern SP being shown,a change occurs in brightness distribution. Therefore, detection of achange in brightness distribution of the deep region is favorable fordetermination of a change in operation status of the treatmentinstrument, more specifically, determines whether the treatmentinstrument is activated or deactivated. Note that an entirety of theB-mode image may be subject to analysis or a particular region otherthan the deep region may be subject to analysis.

Next, in step S106 in FIG. 5 , system control section 18 controls imageprocessing section 14 (image analysis section 142) to determine whetheror not the operation status of the treatment instrument has changed,based on a result of the analysis.

As illustrated in FIGS. 6A and 6B, in a case where the treatmentinstrument has been switched from a non-operating state to an operatingstate, high-brightness spray pattern SP is shown, causing an increase ofhigh brightness-side frequencies. On the other hand, in a case where thetreatment instrument has been switched from an operating state to anon-operating state, high-brightness spray pattern SP disappears,causing a decrease in high brightness-side frequencies. Therefore,comparison between a brightness distribution obtained last time and abrightness distribution obtained the present time enables determinationof whether or not the operation status of the treatment instrument haschanged.

Also, in the graphs in FIGS. 6A and 6B, when the treatment instrument isin an operating state (see FIG. 6B), a mean and variance of brightnessvalues are large in comparison with a case where the treatmentinstrument is in a non-operating state (see FIG. 6A). Therefore, whetheror not the operation status of the treatment instrument has changed canbe determined using a mean and variance of brightness values calculatedfrom a brightness distribution. For example, as illustrated in FIG. 6C,whether the treatment instrument is in an operating state or in anon-operating state can be determined according to a linear discriminantusing a set of a mean and variance of brightness values (means,variance). Also, for example, whether treatment instrument is in anoperating state or in a non-operating state may be determined bycomparing one of the mean and the variance of brightness values with athreshold value for the one.

In a case where the operation status of the treatment instrument haschanged (“YES” in step S106), the processing proceeds to the processingin the step S107. In a case where the treatment instrument has beenactivated from an inactive state and treatment (suction) has beenstarted or in a case where the treatment instrument has been deactivatedfrom an active state and the treatment has been finished (which may be atemporary end), the processing in step S107 is performed. In a casewhere the operation status of the treatment instrument has not changed(“NO” in step S106), the processing proceeds to the processing in stepS101. In this case, the treatment instrument is kept inactive or keptactive, display of second display image D2 is maintained and only thelive image displayed as first display image D1 is updated.

In step S107, system control section 18 controls image storage section15 to read out a B-mode image obtained during a non-treatment period inwhich the treatment instrument is a non-operating state.

More specifically, in a case where the treatment instrument has beenswitched from a non-operating state to an operating state, a B-modeimage before treatment is read out. In this case, the read-out B-modeimage is preferably one immediately before the treatment instrumententers the operating state.

Also, in a case where the treatment instrument has been changed from anoperating state to a non-operating state, a B-mode image after thetreatment is read out. For example, in step S106, arrangement is made soas to, in a case where the status has been maintained for a certainperiod of time after the change in brightness distribution in thepredetermined region, determine that the operation status of thetreatment instrument has changed, enabling reading out a still imageduring a non-treatment period (after treatment) in which no spraypattern SP is shown.

In step S108, system control section 18 controls image display section16 and display section 17 to display the read-out B-mode image (stillimage during a non-treatment period) as second display image D2. Then,the processing returns to step S101 and repeated until completion of thetreatment.

In a case where the treatment instrument has been switched from anon-operating state to an operating state, display section 17 providestwo-screen display of first display image D1 (live image) and seconddisplay image D2 (still image before the treatment) (see FIG. 7A). Sinceno spray pattern SP is shown in second display image D2, treatmentregion of interest TR can easily be identified. A surgeon can performtreatment while confirming treatment region of interest TR by comparingfirst display image D1 and second display image D2.

Also, in a case where the treatment instrument has been switched from anoperating state to a non-operating state, display section 17 providestwo-screen display of first display image D1 (live image) and seconddisplay image D2 (still image after the treatment) (see FIG. 7B). Sinceno spray pattern SP is shown in second display image D2, treatmentregion of interest TR can easily be identified. Also, since seconddisplay image D2 is a still image after treatment, the surgeon canconfirm a status of progress of the treatment regarding to which extentthe treatment region of interest remains, and thus can properly performthe treatment until the treatment region of interest is fully removed.

Note that in a case where the treatment instrument has been switchedfrom an operating state to a non-operating state and then switched to anoperating state, that is, in a case where treatment is resumed after aninterruption, a still image immediately before the resumption of thetreatment is displayed as second display image D2. Then, in a case wherethe treatment instrument has been switched from the operating state to anon-operating state, a new B-mode image (still image after an end of theresumed treatment) is read out by the processing in steps S107 and S108and second display image D2 is thereby updated.

In the above-described ultrasound image display processing, it ispreferable that when second display image D2 is displayed in step S108,the treatment region of interest is highlighted. Examples of thehighlighting include coloring. As illustrated in FIGS. 7A and 7B,treatment region of interest TR in second display image D2 is shown moreclearly than treatment region of interest TR in first display image D1.

Since a treatment region of interest is softer or more slurry than thesurrounding bone and body tissue, the treatment region of interest isshown with a brightness that is lower than the surroundings. Therefore,it is possible to analyze a B-mode image, detect a tissue region,identify a low-brightness region in the tissue region as a treatmentregion of interest and highlight treatment region of interest TR.

In step S108, as a result of the treatment region of interest in seconddisplay image D2 being subjected to highlighting processing, the surgeoncan confirm to which extent the treatment has been performed and whetheror not the treatment has correctly been performed, by comparing theimages before and after the treatment and thus can perform the treatmentproperly. In other words, the surgeon can easily identify a treatmentregion of interest irrespective of the level of his/her skills and thuscan more properly perform the treatment.

As described above, ultrasound diagnostic apparatus 1 according to theembodiment is an ultrasound diagnostic apparatus for generating anddisplaying an ultrasound image corresponding to reflected ultrasoundreflected inside a subject, the apparatus including: B-mode imagegeneration section 141 that generates a B-mode image based on areception signal corresponding to the reflected ultrasound; imageanalysis section 142 (determination section) that analyzes the B-modeimage and determines an operation status of a treatment instrument usedfor treatment; and image display section 16 that based on a result ofthe determination by image analysis section 142, displays first displayimage D1 including a current B-mode image and second display image D2including a B-mode image obtained when the treatment instrument is in anon-operating state in such a manner that first display image D1 andsecond display image D2 are aligned.

Also, the ultrasound image display method according to the embodiment isan ultrasound image display method for generating and displaying anultrasound image corresponding to reflected ultrasound reflected insidea subject, the method including: a first step of generating a B-modeimage based on a reception signal corresponding to the reflectedultrasound (step S103 in FIG. 5 ); a second step of analyzing the B-modeimage and determining an operation status of a treatment instrument usedfor treatment (steps S105 and S106 in FIG. 5 ) and a third step of,based on a result of the determination in the second step, displayingfirst display image D1 including a current B-mode image and seconddisplay image D2 including a B-mode image obtained when the treatmentinstrument is in a non-operating state in such a manner that firstdisplay image D1 and second display image D2 are aligned (steps S107 andS108 in FIG. 5 ).

Also, the program according to the embodiment causes system controlsection 18 (computer) in ultrasound diagnostic apparatus 1 forgenerating and displaying an ultrasound image corresponding to reflectedultrasound reflected inside a subject, to perform: first processing forgenerating a B-mode image based on a reception signal corresponding tothe reflected ultrasound (step S103 in FIG. 5 ); second processing foranalyzing the B-mode image and determining an operation status of atreatment instrument used for treatment (steps S105 and S106 in FIG. 5); and third processing for, based on a result of the determination bythe second processing, displaying first display image D1 including acurrent B-mode image and second display image D2 including a B-modeimage obtained when the treatment instrument is in a non-operating statein such a manner that first display image D1 and second display image D2are aligned (steps S107 and S108 in FIG. 5 ).

This program is provided via, for example, a computer-readable removablestorage medium (which may be an optical disk, a magneto-optical disk ora memory card) with the program stored therein. Also, for example, thisprogram can be provided by being downloaded via a network from a serverthat holds the program.

According to ultrasound diagnostic apparatus 1, the ultrasound imagedisplay method and the program according to the embodiment, even whenvisibility of treatment region of interest TR is lowered by spraypattern SP in first display image D1 including a live image, no spraypattern SP is shown in second display image D2 including a still imageduring a non-treatment period, the still image being obtained when thetreatment instrument is in a non-operating state, and thus visibility oftreatment region of interest TR is ensured. Therefore, a surgeon canproperly perform treatment while confirming treatment region of interestTR in second display image D2.

Also, the operation status of the treatment instrument is determined bymeans of image analysis and thus there is no need to provide a specialinterface for connection with the treatment instrument in ultrasounddiagnostic apparatus 1. Therefore, reduction in cost of ultrasounddiagnostic apparatus 1 can be achieved.

Also, in ultrasound diagnostic apparatus 1, image analysis section 142(determination section) determines whether the treatment instrument isactivated or deactivated. Consequently, ultrasound diagnostic apparatus1 can properly respond to a case where noise (for example, spray patternSP) is shown in a B-mode image depending on the operation status of thetreatment instrument.

Also, in ultrasound diagnostic apparatus 1, image analysis section 142(determination section) determines a change in operation status of thetreatment instrument. Consequently, proper second display image D2 canbe displayed according to a case where the treatment instrument has beenswitched from a non-operating state to an operating state or a casewhere the treatment instrument has been switched from an operating stateto a non-operating state.

Also, in ultrasound diagnostic apparatus 1, image analysis section 142(determination section) determines the operation status of the treatmentinstrument based on a change in brightness distribution in apredetermined region in a B-mode image.

More specifically, image analysis section 142 (determination section)determines the operation status of the treatment instrument based on atleast one of a mean and variance of brightness values in thepredetermined region.

Consequently, the operation status of treatment instrument can bedetermined by relatively simple processing and thus a processing load onsystem control section 18 can be reduced.

Also, in ultrasound diagnostic apparatus 1, a predetermined region thatis subject to image analysis is a deep region in the B-mode image.Consequently, a change in brightness distribution accompanying a changein operation status of the treatment instrument is conspicuouslyindicated, enabling easy and correct determination of the operationstatus of the treatment instrument.

Also, in ultrasound diagnostic apparatus 1, when the treatmentinstrument has been switched from a non-operating state to an operatingstate, image display section 16 displays second display image D2including a B-mode image obtained immediately before the switching.Consequently, no spray pattern SP is shown in second display image D2and thus treatment region of interest TR can easily be identified,enabling the surgeon to proceed treatment while confirming treatmentregion of interest TR by comparing first display image D1 and seconddisplay image D2 with each other.

Also, in ultrasound diagnostic apparatus 1, when the treatmentinstrument has been switched from an operating state to a non-operatingstate, image display section 16 displays second display image D2including a B-mode image immediately after the switching. Since seconddisplay image D2 is a still image after treatment, the surgeon canconfirm a status of progress of the treatment regarding to which extentthe treatment region of interest remains and thus can properly performthe treatment until completion of removal of the treatment region ofinterest.

Also, in ultrasound diagnostic apparatus 1, image display section 16highlights the treatment region of interest in the second display image.More specifically, the treatment region of interest has a brightnessthat is lower than that of a region around the treatment region ofinterest. Consequently, the surgeon can easily identify the treatmentregion of interest regardless of the level of his/her skills and canfurther properly perform the treatment.

Furthermore, the present embodiment also discloses an aspect of theinvention as follows.

Ultrasound diagnostic apparatus 1 according to the embodiment is anultrasound diagnostic apparatus for generating and displaying anultrasound image corresponding to reflected ultrasound reflected insidea subject, the apparatus including: B-mode image generation section 141that generates a B-mode image based on a reception signal correspondingto the reflected ultrasound; image analysis section 142 (determinationsection) that determines an operation status of a treatment instrumentused for treatment; and image display section 16 that based on a resultof the determination by image analysis section 142, displays firstdisplay image D1 including a current B-mode image and second displayimage D2 including a B-mode image obtained when the treatment instrumentis in a non-operating state in such a manner that first display image D1and second display image D2 are aligned Image display section 16highlights treatment region of interest TR in second display image D2.

Consequently, a surgeon can easily identify a treatment region ofinterest irrespective of the level of his/her skills and thus canproperly perform treatment.

Note that in this case, the determination section may be configured soas to determine the operation status of the treatment instrument basedon a driving signal from the treatment instrument, rather than imageanalysis.

Although an invention made by the present inventor has been describedabove based on an embodiment, the present invention is not limited tothe above embodiment and can be changed without departing from thespirit of the invention.

For example, image display section 16 may be configured so as to displayinformation relating to the area of treatment region of interest TR. Asthe information relating to the area of treatment region of interest TR,for example, the area of a low-brightness region may be indicated by anumerical value in a screen (for example, a lower part of the screen) ormay be indicated by a graph. Indication of the area of thelow-brightness region before treatment and the area of thelow-brightness region after treatment by respective numerical values orgraphs enables visually confirming to which extend treatment has beenperformed. Also, for example, image display section 16 may be configuredto indicate a degree of reduction of the area of the low-brightnessregion after treatment relative to the area of the low-brightness regionbefore the treatment (for example, “−10” when the degree of reduction is10). Consequently, a result of the treatment can easily be confirmed.

Also, a B-mode image obtained during a non-treatment period (beforetreatment), the B-mode image being read out when the treatmentinstrument has been switched from a non-operating state to an operatingstate, may be a B-mode image obtained several frames before thetreatment instrument enters the operating state, rather than a B-modeimage immediately before the treatment instrument enters the operatingstate. This is because in the case of the frame immediately before, aspray pattern may be shown slightly.

Although embodiments of the present invention have been described andillustrated in detail, the disclosed embodiments are made for purpose ofillustration and example only and not limitation. The scope of thepresent invention should be interpreted by terms of the appended claims.

What is claimed is:
 1. An ultrasound diagnostic apparatus for generatingand displaying an ultrasound image corresponding to a reflectedultrasound reflected inside a subject, the apparatus comprising ahardware processor that generates a current B-mode image based on areception signal corresponding to the reflected ultrasound, analyzes thecurrent B-mode image and determines an operation status of a treatmentinstrument used for treatment, the operation status being determinedbased on whether a spray pattern is present in the current B-mode image,and the spray pattern being determined based on a change in a brightnessdistribution in a low or bottom region in the current B-mode image,displays, in response to a determination that the spray pattern ispresent in the current B-mode image, a first display image including thecurrent B-mode image and a second display image including anon-operating state B-mode image obtained when the treatment instrumentis in a non-operating state in such a manner that the first displayimage and the second display image are aligned.
 2. The ultrasounddiagnostic apparatus according to claim 1, wherein the hardwareprocessor determines whether the treatment instrument is activated ordeactivated.
 3. The ultrasound diagnostic apparatus according to claim1, wherein the hardware processor determines a change in the operationstatus of the treatment instrument.
 4. The ultrasound diagnosticapparatus according to claim 1, wherein the hardware processordetermines the operation status of the treatment instrument based on atleast one of an average and variance of brightness values in the low orbottom region in the current B-mode image.
 5. The ultrasound diagnosticapparatus according to claim 1, wherein the hardware processor generatesa live B-mode image and determines a change in operation status byanalyzing the live B-mode image, and when the determination of thechange in operation status is that the treatment instrument has beenswitched from the non-operating state to the operating state, thehardware processor displays the second display image including thenon-operating state B-mode image obtained before the switching.
 6. Theultrasound diagnostic apparatus according to claim 1, wherein thehardware processor generates a live B-mode image and determines a changein operation status by analyzing the live B-mode image, and when thedetermination of the change in operation status is that the treatmentinstrument has been switched from the operating state to thenon-operating state, the hardware processor displays the second displayimage including the non-operating state B-mode image obtained after theswitching.
 7. The ultrasound diagnostic apparatus according to claim 1,wherein the hardware processor highlights a treatment region of interestin the second display image.
 8. The ultrasound diagnostic apparatusaccording to claim 7, wherein the treatment region of interest isidentified by the hardware processor as having a brightness that islower than that of a region around the treatment region of interest. 9.The ultrasound diagnostic apparatus according to claim 1, wherein thelow or bottom region is in a bottom 20% of the current B-mode image. 10.An ultrasound image display method for generating and displaying anultrasound image corresponding to a reflected ultrasound reflectedinside a subject, the method comprising: generating a current B-modeimage based on a reception signal corresponding to the reflectedultrasound; analyzing the current B-mode image and determining anoperation status of a treatment instrument used for treatment, theoperation status being determined based on whether a spray pattern ispresent in the current B-mode image, and the spray pattern beingdetermined based on a change in a brightness distribution in a low orbottom region in the current B-mode image; and displaying, in responseto a determination that the spray pattern is present in the currentB-mode image, a first display image including the current B-mode imageand a second display image including a non-operating state B-mode imageobtained when the treatment instrument is in a non-operating state insuch a manner that the first display image and the second display imageare aligned.
 11. A non-transitory computer-readable recording mediumstoring a program for causing a computer in an ultrasound diagnosticapparatus for generating and displaying an ultrasound imagecorresponding to a reflected ultrasound reflected inside a subject, toperform: first processing for generating a current B-mode image based ona reception signal corresponding to the reflected ultrasound; secondprocessing for analyzing the current B-mode image and determining anoperation status of a treatment instrument used for treatment, theoperation status being determined based on whether a spray pattern ispresent in the current B-mode image, and the spray pattern beingdetermined based on a change in a brightness distribution in a low orbottom region in the current B-mode image; and third processing fordisplaying, in response to a determination that the spray pattern ispresent in the current B-mode image by the second processing, a firstdisplay image including the current B-mode image and a second displayimage including a non-operating state B-mode image obtained when thetreatment instrument is in a non-operating state in such a manner thatthe first display image and the second display image are aligned.
 12. Anultrasound diagnostic apparatus for generating and displaying anultrasound image corresponding to a reflected ultrasound reflectedinside a subject, the apparatus comprising a hardware processor thatgenerates a current B-mode image based on a reception signalcorresponding to the reflected ultrasound, determines an operationstatus of a treatment instrument used for treatment, the operationstatus being determined based on whether a spray pattern is present inthe current B-mode image, and the spray pattern being determined basedon a change in a brightness distribution in a low or bottom region inthe current B-mode image, displays, in response to a determination thatthe spray pattern is present in the current B-mode image, a firstdisplay image including the current B-mode image and a second displayimage including a non-operating state B-mode image obtained when thetreatment instrument is in a non-operating state in such a manner thatthe first display image and the second display image are aligned, andhighlights a treatment region of interest in the second display image.13. The ultrasound diagnostic apparatus according to claim 12, whereinthe hardware processor displays information relating to an area of thetreatment region of interest.